Teddy Roosevelt was a severe asthmatic as a child. His attacks were so severe at night that they would blend with his dreams and cause near death visions. At some point in his childhood, he famously embraced "the strenuous life" and started by remaking his body. He developed an iron willpower, learned to box and lift weights. Throughout his life as a cowboy, rough rider, and President, he was renowned for his boundless energy and courage.

He seems to have inspired "Chuck Norris" stories avant-la-lettre: in one, he was walking up to give a speech when he was shot by a would-be assassin. The bullet penetrated the bible he had in his front pocket and lodged into his chest. He stood up, gave a two hour speech, and then went to the hospital. Some versions of the story have him starting the speech holding up the bloody bible and announcing, "You see, it takes more than one bullet to kill a Bull Moose!"

John F. Kennedy was sick throughout high school, with a "blood illness." He was originally enrolled at Princeton and had to drop out due to his sickness; his father took him to Europe for a year to heal and then wrote the Harvard admissions to get him enrolled there. Young pictures of him look sickly.

As a senator, and later as president, JFK was famous for his vigor (vigah?). He discussed physical fitness in numerous speeches; critics, like Ayn Rand, did not deny his vigor but instead tried to use it against him, as evidence of his thirst for power. He exercise frequently, to clear his mind, during the Cuban missile crisis. Stories of his sickly childhood only emerged later.

Augustus Caesar, the founder of the Roman Empire, and a leader so influential that his contemporaries practically forgot that they had grown up in a republic, was also sickly in his youth. He was an unimpressive soldier, suffered from typhoid fever, and preferred writing poetry and reading plays. The assassination of his adoptive father, Julius, seemed to galvanize him and he won a series of impressive victories over his rival, Marc Antony.

Seneca, the Roman Stoic philosopher, whose influence was everywhere in the early Roman Empire, from plays, to business, to governing Rome, to tutoring Emperors, to Stoic philosophy, suffered from asthma and other illnesses his whole life. As he writes, "If you meet sickness in a sensible manner, do you really think you are achieving nothing? War and the battlefront are not the only spheres in which proof is to be had of a spirited and fearless character … [make] the fight with illness a good one."